Because it was about revolution, not reformation.
Luther thought he was bringing to the pope specific errors in doctrine and practice. He thought the pope would be glad to know about the problems, and would correct them. That was a true attempt at reform.
Of course they kicked him out, which which tempt anyone to revolution.
Yet unlike the “reformed” sects, all the Lutherans did was remove the false and harmful stuff, leaving in everything else.
You realize Lutherans are criticized by protestants for being too Catholic, yes?